. >> logan johnson, national weather service. >> ours is located near san jose so it doesn't cover the north bay so we use your radar as a key piece of puzzle to understand what is going to. >> what doppler radar generally it detects motion and the movement of systems that produce precipitation and intensity and the direction. the speed at which it is moving. all these things is what doppler radar does. >> to go down to street level to what is happening right in the neighborhood. you can say there is going from elm street to oak street in five minutes. that is the biggest advantage of having where we have it. think of the lead time you are going to get to see a storm coming in. that is getting people prepared. >> i'll never forget this woman who was in mill valley. i was out there reporting on a landslide there. her home devastated. everything she has ever had gone. she came up to me and she said thank you. she said your forecast, abc7's forecast being able to let me know days in advance, she was able to get her most precious things out of there and because we were able to give her tha